B- -a-Pinanyl-9-borabicyclo nonane

Pictet-Spengler cyclization, 161 Pinacol rearrangements, 51 B-(3>a-Pinanyl-9-borabicyclo[3.3.1 ]-nonane, 320-321 Piperidine, 183 Piperidine enamines, 16 Piperidines, 18 Piperonal, 232 Piperylene, 372 N-Pivaloylaniline, 69 Platinum catalysts, 321 Podophyllotoxin, 165 Polygodial, 167 Polymethoxyarenes, 368 Polymethylpyrimidines, 345 Polynucleotides, 88 Polyphosphate ester, 437 Polyphosphoric acid, 321-322 Potassioacetone, 73 Potassium-Alumina, 322 Potassium bis(trimcthylsilyl)amide, 38 Potassium f-butoxide, 323 Potassium carbonate, 323 Potassium-18-Crown-6, 322 Potassium cyanide, 324 Potassium cyclopentadienide, 111 Potassium 2,6-di-f-butyl-4-methylphen-oxide, 48 

Midland, M. M., Petre, J. E., Zderic, S. A., Kazubski, A. Thermal reactions of B-alkyl-9-borabicyclo[3.3.1]nonane (9-BBN). Evidence for unusually facile dehydroboration with B-pinanyl-9-BBN. J. Am. Chem. Soc. 1982,104, 528-531. 

By cyclization reactions Camphor- 10-sulfonic acid, 62 Diethoxy triphenylphosphorane, 109 Diisobutylaluminum hydride, 115 B-3-Pinanyl-9-borabicyclo[3.3.1]-nonane, 249 Sodium nitrite, 282 a,(3-Epoxy alcohols I-Butyl hydroperoxide-Dialkyl tartrate-Titanium(IV) isopropoxide, 51 I-Butyl hydroperoxide-Dibutyltin oxide, 53 

Midland, M. M., McDowell, D. C., Hatch, R. L., Tramontane, A. Reduction of a,P-acetylenic ketones with B-3-pinanyl-9-borabicyclo[3.3.1]nonane. High asymmetric induction in aliphatic systems. J. Am. Chem. Soc. 1980,102, 867-869. 

Midland, M. M., Tramontane, A., Zderic, S. A. Preparation of optically active benzyl-a-d alcohol via reduction by B-3a-pinanyl-9-borabicyclo[3.3.1]nonane. A new highly effective chiral reducing agent. J. Am. Chem. Soc. 1977, 99, 5211-5213. 

Addition of alane and borane to alkenes affords a host of alkylated alanes and boranes with various reducing properties (and sometimes bizarre names) diisobutylalane (Dibal-H ) [104], 9-borabicyclo[3.3.1]nonane (9-BBN) (prepared from borane and 1,5-cyclooctadiene) [705], mono- [106,107] and diiso-pinocampheylborane (B-di-3-pinanylborane) (both prepared from borane and optically active a-pinene) [108], isopinocampheyl-9-borabicyclo[3.3.1 Jnonane alias B-3-pinanyl-9-borabicyclo[3.3.1]nonane (3-pinanyl-9-BBN) (prepared from 9-borabicyclo [3.3.1]nonane and a-pinene) [709], NB-Enanthrane prepared from 9-borabicyclo[3.3.1]nonane and nopol benzyl ether) [770] and others.  

Enantioselective reduction is not possible for aldehydes, since the products are primary alcohols in which the reduced carbon is not chiral, but deuterated aldehydes RCDO give a chiral product, and these have been reduced enantioselectively with B-(3-pinanyl)-9-borabicyclo[3.3.1]nonane (Alpine-Borane) with almost complete optical purity.  

Acetylenic ketones are important synthetic intermediates in the synthesis of a variety of natural products. Optically active propargyl alcohols of either configuration are readily available in high optical purity by asymmetric reduction of propargyl ketones with B-3-pinanyl-9-borabicyclo(3.3.1)nonane (Eq. 31). 

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