BARTON Nitrite photolysis

The Barton nitrite photolysis reaction involves the conversion of a nitrite ester 1 to a y-oximino-alcohol 3 by photolysis involving the homolytic cleavage of a nitrogen oxygen bond followed by hydrogen abstraction.  

In 1960, Barton took a vacation in Cambridge, Massachusetts where he worked in a small outfit called the Research Institute for Medicine 

The Barton nitrite photolysis reaction has played an important role in the synthesis of natural products and has been previously reviewed. The invention of this reaction enabled chemists to convert remote, un-activated, sp hybridized carbon atoms on conformationally constrained hydrocarbons. 

The Barton nitrite photolysis was used in the conversion of nitrite of corticosterone acetate (5) to 6 during the synthesis of aldosterone actetate.  

Suginome and coworkers prepared 10 by photolysis of steroidal 20a-ol nitrite 9 which was then converted into 12-deoxofiikujusonorone in ten-steps.  

Barton, D. H. R. Beaton, J. M. Geller, L. E. Pechet, M. M. J. Am. Chem. Soc. 1960, 82, 2640. In 1960, Derek Barton took a vacation in Cambridge, Massachusetts he worked in a small research institute called the Research Institute for Medicine and Chemistry. In order to make the adrenocortical hormone aldosterol. Barton invented the Barton nitrite photolysis by simply writing down on a piece of paper what he thought would be an ideal process. His skilled collaborator. Dr. John Beaton, was able to reduce it to practice. They were able to make 40 to 50 g of aldosterol at a time when the total world supply was only about 10 mg. Barton considered it his most satisfying piece of work. 

Snginome, H. CRC Handbook of Organic Photochemistry and Photobiology 2nd edn. 2004,102/1-102/16. (Review). 

Name Reactions A Collection of Detailed Mechanisms and Synthetic Applications, DOI 10.1007/978-3-319-03979-4 15, Springer International Publishing Switzerland 2014 

Barton nitrite photolysis. In Name Reactions for Homologations-Part / Li, J. J., Ed. Wiley Hoboken, NJ, 2009, pp 633-647. (Review). 

Nitric oxide radical is a stable and therefore, long-lived radical 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 13, Springer-Verlag Berlin Heidelberg 2009 

Condensation of o-nitrotoluene derivatives with formamide aeetals, followed by reduetion of die tr ms-P-dimethylamino-2-nitrostyrene to furnish indole derivatives. 

---

Barton Reaction (Barton Nitrite Photolysis Reaction)... 

Scheme 76 Barton nitrite photolysis of a steroidal compound 277 to afford an oxime 199.

Note that this is not a chain process. The reaction, known as the Barton nitrite photolysis, was developed to functionalize steroids in positions that... 

Other examples from the group include the black light promoted selective halogenation of cydoalkenes, reporting the efficient mono-bromination using B12 and chlorinations using CI2 and SOCI2 within a biphasic reaction system, and the Barton nitrite photolysis used for the conversion of nitrite derivative (17) to steroid (18) (Scheme 6.7) [11]. 

Scheme 6.7 Illustration of the Barton nitrite photolysis used in the synthesis of a complex saturated alcohol.

---