Alanine methyl ester (I) was protected by N-alkylation with benzyl bromide to afford (II), which was further reduced to amino alcohol (III) using LiAlH4. Swern oxidation of (III) provided aldehyde (IV). Addition of the Grignard reagent obtained from 1-bromopentadecane (A) to aldehyde (IV) produced the anti-aminoalcohol (V). The N-benzyl groups were finally removed by catalytic hydrogenolysis.

In a different procedure, dibenzyl malonate (VI) was alkylated with tetradecyl bromide (B) to afford (VII). This was then condensed with N-phthaloyl-L-alanyl chloride (VIII) in the presence of NaH, and the resulting keto diester (IX) was subjected to hydrogenolysis of the benzyl esters and further thermal decarboxylation to furnish ketone (X). Ketone reduction with simultaneous partial reduction of the phthaloyl group yielded (XI) and (XII) as a diastereomeric mixture. After chromatographic separation, the desired isomers were deprotected by reductive cleavage with NaBH4 to provide the corresponding amino alcohol.

Alanine methyl ester (I) was protected by N-alkylation with benzyl bromide to afford (II), which was further reduced to amino alcohol (III) using LiAlH4. Swern oxidation of (III) provided aldehyde (IV). Addition of the Grignard reagent obtained from 1-bromopentadecane (A) to aldehyde (IV) produced the anti-aminoalcohol (V). The N-benzyl groups were finally removed by catalytic hydrogenolysis.

In a different procedure, dibenzyl malonate (VI) was alkylated with tetradecyl bromide (B) to afford (VII). This was then condensed with N-phthaloyl-L-alanyl chloride (VIII) in the presence of NaH, and the resulting keto diester (IX) was subjected to hydrogenolysis of the benzyl esters and further thermal decarboxylation to furnish ketone (X). Ketone reduction with simultaneous partial reduction of the phthaloyl group yielded (XI) and (XII) as a diastereomeric mixture. After chromatographic separation, the desired isomers were deprotected by reductive cleavage with NaBH4 to provide the corresponding amino alcohol.