| abstract |
The method for the preparation of vitamin K2 of the formula MK-7 is characterized by the attachment of a hexaprenyl chain forming "all-trans" to a monoprenyl derivative of menadiol according to the synthetic strategy "1 + 6". According to the invention, α-sulfonyl carbonate produced in situ from the protected monoprenyl monadiol of formula (II), wherein R1 represents a C1-3-alkyl group, is reacted with a hexaprenylal halide of formula (VII), wherein X represents an atom. halogen, preferably bromine, both Z 'and Z "represent H or one of Z' and Z" represents H and the other represents phenylsulfonyl group -SO2Ph in the alkylation reaction. The hexaprenylyl halide of formula (VII) is obtained by coupling two triprenyl units to the alkylation reaction, with or without separation of the intermediates. |