合成路线1

The 6-cyanohexanoic ester (VII), intermediate in the synthesis of 180072 (see intermediate (XLI) in scheme no. 18007204a) has been obtained as follows: the reaction of 1,6-heptadien-4-ol (I) with BuLi, CO2, and I2 in THF gives the cyclic carbonate (II), which is treated with Ts-OH in acetone to yield the acetonide (III). The reaction of the iodine atom of (III) with KCN in hot DMSO affords the nitrile (IV), which is oxidized at the terminal double bond with OsO4 and NaIO4, or O3 and Me2S, to provide the carbaldehyde (V). The oxidation of (V) with CrO3/H2SO4 in acetone gives the carboxylic acid (VI), which is finally esterified with tert-butanol by means of DCC and DMAP in dichloromethane, yielding the target ester intermediate (VII).