content_image/910867.jpg content_image/910874.jpg content_image/910875.jpg content_image/910876.jpg content_image/910877.jpg content_image/910878.jpg
wherein Et denotes an ethyl group. 

To a mixture of 120 g ofmethacrylic acid chloride, 300 g of 17a-methylandrostan-17~-ol-3-one, and 1,500 g of tolu› ene was added 111 g of triethylamine while stirring under ice-cooling. Thereafter, the mixture was stirred at room temperature for 16 hours. The mixture was then subjected to a usual aqueous post-treatment (aqueous work-up), and the solvent was distilled off to obtain a crude product. The product was purified by column chromatography to obtain an intended product, Monomer 1. 

[Synthesis Example 1-2] Synthesis of Monomer 2 

Monomer 2 was synthesized in the same manner as in Synthesis Example 1-1 except that 17a-methylandrostan- 17~-ol-3-one was changed to methyltestosterone. 

[Synthesis Example 1-3] Synthesis of Monomer 3 

Monomer 3 was synthesized in the same manner as in Synthesis Example 1-1 except that 17a-methylandrostan- 17~-ol-3-one was changed to ~-hydroxy-17-methylan› drosta-l,4-dien-3-one. 

[Synthesis Example 1-4] Synthesis of Monomer 4 

Monomer 4 was synthesized in the same manner as in Synthesis Example 1-1 except that 17a-methylandrostan- 17~-ol-3-one was changed to ~-hydroxy-17-methylan› drosta-4,9(11 )-dien-3-one. 

[Synthesis Example 1-5] Synthesis of Monomer 5 

Monomer 5 was synthesized in the same manner as in Synthesis Example 1-1 except that 17a-methylandrostan- 17~-ol-3-one was changed to mestranol. 

[Synthesis Example 1-6] Synthesis of Monomer 6 

Monomer 6 was synthesized in the same manner as in Synthesis Example 1-1 except that methacrylic acid chloride 65 was changed to methacrylic acid-5-carboxylic acid-4-oxatri- cyclo[ 4.2.1.0 $^{3}$.?]nonan-5-one-2-yl. 

-continued 

<img src='content_image/910867.jpg'>

Structures of Monomers 1 to 6 synthesized in Synthesis Examples 1-1 to 1-6 are shown below. 

<img src='content_image/910874.jpg'>

<img src='content_image/910875.jpg'>

<img src='content_image/910876.jpg'>

<img src='content_image/910877.jpg'>

<img src='content_image/910878.jpg'>

