| abstract |
PREPARATION OF DIAZAPETALENE DERIVATIVES THROUGH THE EPOXIDATION OF DIIDROPIRRONS. The present invention relates to a process for the preparation of a compound of formula (1), in which R ^ 1 ^ is Pg ^ 1 ^ or P ~ 1 ~ '; P ~ 1 ~ 'is CO-hydrocarbyl; P ~ 2 ~ is CH ~ 2 ~, O or N-Pg ^ 2 ^; and Pg ^ 1 ^ and Pg ^ 2 ^ are each independently nitrogen protecting groups; (i) reacting a compound of formula (II) with dioxirane to form an epoxide of formula (III); where x is selected from CN, CH ~ 2 ~ N ~ 3 ~, CH ~ 2 ~ NH-Pg ^ 2 ^, ONH-Pg ^ 2 ^, NHNH-Pg ^ 2 ^, N (Pg ^ 2 ^) NH- Pg ^ 2 ^; (ii) converting a compound of formula (III) to a compound of formula (1) |