Claims
- 1. A process for producing (S) 2-(6-methoxy-2-naphthyl)propionic acid or an ester thereof which comprises heating a stereoisomer, having an absolute configuration of (S), of an optically active ketone of the formula: ##STR48## wherein Z is halogen, hydroxy, protected hydroxy or a sulfonyloxy group of the formula ##STR49## wherein R.sub.2 is alkyl, cycloaklyl, alkenyl, alkynyl, aryl or aralkyl, in the substantial absence of any other stereoisomer of said ketone, with an ortho ester in the presence of an acid at an elevated temperature in excess of about 80.degree. C. for a time sufficient to afford the corresponding ester of (S) 2-(6-methoxy-2-naphthyl)propionic acid in the substantial absence of any other stereoisomer thereof.
- 2. The process of claim 1 wherein said acid is an organic or inorganic acid.
- 3. The process of claim 2 wherein said acid is sulfuric acid.
- 4. The process of claims 1, 2 or 3 wherein said ketalizing agent is a trialkyl orthoformate.
- 5. The process of claim 4 wherein said ketalizing agent is trimethyl orthoformate or triethyl orthoformate.
Parent Case Info
This is a division of application Ser. No. 872,561, filed Jun. 10, 1986, now U.S. Pat. No. 4,749,804, incorporated herein by reference, which is a division of application Ser. No. 602,834 filed Apr. 23, 1984, now U.S. Pat. No. 4,605,758, which is a continuation of application Ser. No. 329,672, filed Dec. 11, 1981, now abandoned.
Foreign Referenced Citations (2)
Number |
Date |
Country |
34871 |
Sep 1981 |
EPX |
35305 |
Sep 1981 |
EPX |
Non-Patent Literature Citations (3)
Entry |
Seebach, Angew. Chem. Internat. Ed., pp. 619-621, (1968). |
Smissman, J. Org. Chem., pp. 4005-4007, (1965). |
Tsuchihashi, Tetrahedron Letters, 22(43), pp. 4305-4308. |
Divisions (2)
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Number |
Date |
Country |
Parent |
872561 |
Jun 1986 |
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Parent |
602834 |
Apr 1984 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
329672 |
Dec 1981 |
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