1: 3-[(4S,5S)-4,5-Bis(1-methoxycyclopentyl)-1,3,2-dioxoborolan-2-yl]propiophenone O-methyloxime With dimethylsulfide borane complex in tetrahydrofuran T=-15 - 20°C; Reduction; 16 h; 2: With sodium hydroxide; dihydrogen peroxide in water oxidative cleavage; 3: acetylation agent Acetylation;