This MuleSoft project provides a way to convert RAML/OAS to WSDL. You can find the project here.
https://github.com/djuang1/wsdl-generator-mule4
It uses the following libraries/projects:
- OpenAPI Generator – https://openapi-generator.tech/
- WebAPI Parser – https://github.com/raml-org/webapi-parser
You can see a working example here: https://wsdl-generator.us-e1.cloudhub.io/console/