Enantioselective synthesis of 2-substituted 6- and 7-membered lactones via α-alkylation of lactone hydrazones

Article abstract of DOI:10.1055/s-1995-4431

2-Alkyl-substituted lactones 4 were synthesized in good overall yields and high enantiomeric purities (ee = 90-94%) by deprotonation and alkylation of the corresponding lactone SAMP-hydrazones 2 and subsequent oxidative cleavage of the product hydrazones 3 by ozonolysis. The lactone hydrazones 2, in turn, were prepared in good yields by silver promoted cyclization of ω-chloroalkanohydrazides 1.