Studies relating to phthiocerol. Part V. Phthiocerol A and B

Abstract

Phthiocerol B, consisting of two homologous β-diols closely related to the previously known diols CH₃·[CH₂]_n·CH(OH)·CH₂·CH(OH)·[CH₂]₄·CH(CH₃)·CH(OCH₃)·CH₂·CH₃, now named phthiocerol A, has been isolated, together with other products, from crude phthiocerol (obtained from human tubercle bacilli). Comparative mass spectrometric and nuclear magnetic resonance studies of phthiocerol A and B, as well as their ethylidene acetals, are described and evidence is presented that phthiocerol B is a mixture of homologues having the structure CH₃·[CH₂]_n·CH(OH)·CH₂·CH(OH)·[CH₂]₄·CH(CH₃)·CH(OCH₃)·CH₃ where n is 22 and 20, respectively. High-resolution infrared studies of phthiocerol A and B are also reported.