There is provided an α-carbonyl alkenyl ester and a preparation method therefor, and the α-carbonyl alkenyl ester is further used to react with a primary or secondary amine to prepare an amide. The two reactions are combined to develop an amide bond and peptide bond formation method that directly use carboxylic acids and amines as starting materials and allenones as a condensing reagent. The α-carbonyl alkenyl ester corresponding to an α-amino acid serves as a peptide synthesis building block and is used in solid phase peptide synthesis. The method is carried out under mild reaction conditions, simple to operate, and has a high yield. Compared with existing amide bond condensation reagents, the allenones have the advantages of being simple to prepare, having good stability, a low molecular weight, not racemizing when activating α-chiral carboxylic acids, and is a novel amide bond and peptide bond condensing reagent.

There is provided an α-carbonyl alkenyl ester and a preparation method therefor, and the α-carbonyl alkenyl ester is further used to react with a primary or secondary amine to prepare an amide. The two reactions are combined to develop an amide bond and peptide bond formation method that directly use carboxylic acids and amines as starting materials and allenones as a condensing reagent. The α-carbonyl alkenyl ester corresponding to an α-amino acid serves as a peptide synthesis building block and is used in solid phase peptide synthesis. The method is carried out under mild reaction conditions, simple to operate, and has a high yield. Compared with existing amide bond condensation reagents, the allenones have the advantages of being simple to prepare, having good stability, a low molecular weight, not racemizing when activating α-chiral carboxylic acids, and is a novel amide bond and peptide bond condensing reagent.

A peptide having a fluoroalkyl group as its side chain and a method for producing, which comprises condensing a compound represented by the formula (6-2) or (6-4), where means that an asymmetric carbon atom has an absolute configuration of S or R, Rf is a C.sub.1-30 alkyl group which is substituted with at least two fluorine atoms, and which may further be substituted with a halogen atom other than a fluorine atom (when the C.sub.1-30 alkyl group is a C.sub.2-30 alkyl group, it may have 1 to 5 etheric oxygen atoms between carbon atoms), and R.sup.2 is a protecting group for the amino group, with a fluorinated amino acid having its carboxy group protected, an amino acid having its carboxy group protected, a fluorinated peptide having its C-terminal protected, or a peptide having its C-terminal protected.

A peptide having a fluoroalkyl group as its side chain and a method for producing, which comprises condensing a compound represented by the formula (6-2) or (6-4), where means that an asymmetric carbon atom has an absolute configuration of S or R, Rf is a C.sub.1-30 alkyl group which is substituted with at least two fluorine atoms, and which may further be substituted with a halogen atom other than a fluorine atom (when the C.sub.1-30 alkyl group is a C.sub.2-30 alkyl group, it may have 1 to 5 etheric oxygen atoms between carbon atoms), and R.sup.2 is a protecting group for the amino group, with a fluorinated amino acid having its carboxy group protected, an amino acid having its carboxy group protected, a fluorinated peptide having its C-terminal protected, or a peptide having its C-terminal protected.

The present disclosure describes compounds of Formula (I) and pharmaceutically acceptable salts thereof:

##STR00001##

The present invention provides a bioconjugation method and compounds for use therein. The bioconjugation method comprises the step of conjugating a biological molecule containing a first unsaturated functional group with a payload comprising a second unsaturated functional group, wherein the first and second unsaturated functional groups are complementary to each other such that conjugation is a reaction of said functional groups via a Diels-Alder reaction which forms a cyclohexene ring.

The present invention provides a bioconjugation method and compounds for use therein. The bioconjugation method comprises the step of conjugating a biological molecule containing a first unsaturated functional group with a payload comprising a second unsaturated functional group, wherein the first and second unsaturated functional groups are complementary to each other such that conjugation is a reaction of said functional groups via a Diels-Alder reaction which forms a cyclohexene ring.

The present disclosure provides a method of preparing a compound of Formula I, wherein R.sup.1 is C.sub.1-C.sub.4 alkyl; R.sup.2 is C1-C4 alkyl; and R.sup.3 is selected from the group consisting of C.sub.1-C.sub.6 alkyl, (aryl)alkyl, and (heteroaryl)alkyl in >95% chemical purity and >95% enantiomeric excess. ##STR00001##

The present disclosure provides a method of preparing a compound of Formula I, wherein R.sup.1 is C.sub.1-C.sub.4 alkyl; R.sup.2 is C1-C4 alkyl; and R.sup.3 is selected from the group consisting of C.sub.1-C.sub.6 alkyl, (aryl)alkyl, and (heteroaryl)alkyl in >95% chemical purity and >95% enantiomeric excess. ##STR00001##

Compounds, compositions, and methods for the treatment of Canavan disease are described.