Ответ: (H3C)2C=CH2—(HBr ROOR)—> (H3C)2-CH-CH2Br—(NaOH (H2O) — NaBr)—> (H3C)2CH-CH2OH—( CrO3 C5H5N)—> (H3C)2CH-CHO—(+Ag2O)—> (H3C)2-CH-COOH