88361-07-3Relevant articles and documents
Synthesis of enantioenriched tertiary boronic esters from secondary allylic carbamates. Application to the synthesis of C30 botryococcene
Pulis, Alexander P.,Aggarwal, Varinder K.
, p. 7570 - 7574 (2012/06/16)
Enantioenriched secondary allylic carbamates have been deprotonated with sBuLi and reacted with boronic esters. In contrast to other electrophiles, high α-selectivity was observed and the boronate complexes were formed with almost complete retention of stereochemistry. The boronate complexes underwent a stereospecific 1,2-migration leading to tertiary allylic boronic esters with high er (>98:2). The scope of the reaction has been explored and found to embrace a broad range of both allylic carbamates and boronic esters. The methodology has been applied to an eight-step, stereoselective synthesis of each of the diastereoisomers of C30 botryococcene.
BIOSYNTHESIS OF UNUSUAL ACYCLIC ISOPRENOIDS IN THE ALGA BOTRYOCOCCUS BRAUNII
Wolf, Fred R.,Nemethy, Esther K.,Blanding, Jonathan H.,Bassham, James A.
, p. 733 - 738 (2007/10/02)
A 'resting state' isolate of the hydrocarbon-producing alga Botryococcus braunii photoassimilated sodium 14C>bicarbonate at rates comparable to fast growing algae, such as Chlorella ( > 150 μg atoms 14C/mg chlorophyll hr).Early in the reaction (up to several min), most of the radioactivity was associated with water-soluble metabolites.However, labeling of hexane-soluble compounds steadily increased from ca 3 percent at 15 sec to over 50 percent of the total incorporated 14C at 60 min.The purified hexane fraction, which consisted of a series of botryococcenes and squalene, constituted a relatively constant proportion (40-45percent) of the total hexane-soluble radioactivity at all bur the earliest time points ( a C30 botryococcene (ca 91 percent) and squalene (ca 8 percent); however, small amounts of radioactivity sequentially appeared in the C31, C32 and C34 botryococcenes.The results of pulse-chase experiments implicated the C30 botryococcene as the precursor of the higher homologues; during the chase, loss of radioactivity from the C30 compound was accompanied by a concomitant increase in the labelling of the C31 and C32 compounds.This study provides further evidence that the relatively slow growth of Botryococcus in culture may result, in part, from the diversion of a large proportion of reduced carbon into energetically expensive compounds and that the slower growth rate in the 'resting state' cannot be totally attributed to an impaired or intrinsically slow metabolism. - Key Wor Index - Botryococcus braunii; Chlorophyceae; alga; biosynthesis acyclic isoprenoids; botryococcenes.
